Mucopolysaccharidosis type II: a scoping review on how to assess this rare disease

Mucopolysaccharidosis type II (MPS II), or Hunter syndrome, is a rare lysosomal storage disorder caused by pathogenic variants in the IDS gene. This condition has specific treatment; therefore, timely diagnosis and adequate follow-up are essential for optimizing patient outcomes. Objective: To synthesize the available evidence on diagnostic and follow-up approaches for MPS II. Methods: Scoping review of ten databases for articles published between 2017 and 2022. Studies involving human participants were included if they addressed diagnostic or follow-up methods for MPS II. We followed the PRISMA-ScR guidelines and conducted qualitative analysis and descriptive statistics to identify trends in diagnostic and follow-up practices. Results: 31 articles were selected. Of these, 23 reported clinical findings, with most articles focusing on neurological (n = 17), skeletal and limbs (n = 16), and head and neck (n = 15) manifestations. Enzyme activity testing was the most reported diagnostic method, although the techniques used were frequently unspecified. Follow-up approaches included imaging studies, clinical assessments, and quality-of-life measurement scales. However, the lack of standardization in methodologies limits the generalizability of findings. Conclusion: This review highlights the need for standardized diagnostic and follow-up protocols for MPS II. Greater transparency in reporting diagnostic methods and a consistent follow-up framework are critical to improving patient care and facilitating research comparisons.